The onion is the most widespread and cultivated form of the leek plant genus. In its most familiar form, it is primarily used as a vegetable.
Occurrence and cultivation of the onion
The best known types are the yellow, the white and the red onion. Onions also vary in taste in sweetness and pungency. The onion plant does not occur in its present form as a wild plant, but its cultivation began over 7,000 years ago. The onion is a biennial plant that is usually grown annually. Modern variations grow 15 to 45 cm high, the leaves are greenish-bluish and resemble fans in shape. The round bulbs of the onion are used as a vegetable in kitchens around the world and have their specific shape and appearance depending on the growing region and type. The best known types are the yellow, the white and the red onion. Onions also vary in taste in sweetness and pungency. Characteristic of their appearance is the round shape and edible tissue of the bulb grown in layers.
Application and use
Onions are mainly used in the preparation of dishes. For use in hot dishes, they are peeled and chopped and heated in a pot or pan with other ingredients. However, some onion-based dishes also exist, such as French onion soup or onion chutneys. In terms of processing, the onion is very versatile. It can be baked, boiled, stewed, fried, roasted, or eaten raw. They are also used as a thickener for sauces or as a food pickled in vinegar. All over the world, the onion is one of the ingredients used daily in the kitchen. The yellow (or brown) onion is particularly fond of caramelization and provides a very good base for sauces, especially in French cuisine. The white onion has a very prominent place in Mexican cuisine, sautéed it gets a golden-brown color and a pleasant sweet taste. The red onion is especially popular in the cuisine of the Middle East, for example in Turkey. Unlike in Germany, where it is used in larger quantities and more as a vegetable, in our country it is used in smaller quantities as a spice. Since onions have particularly large cells, they have long been used in scientific education. Pupils and students are shown onions under a microscope to study the structure of organic cells. The juice of the onion is also used as protection against moths, and rubbed into the skin, the juice can prevent mosquito bites. In the past, onion juice was also used as a polish for glass and copperware, or to protect against rust on iron. The yellow skin of the onion can be used for coloring (for example, soups or sauces, but also clothes).
Importance for health, treatment and prevention
Most types of onions consist of 89% water, 4% sugar, 1% protein, 2% fiber and 0.1% fat. They are rich in vitamin C, vitamin B6 and folic acid. Onion is low in fat and salt, and with only 40 kilocalories per 100 grams, they enrich the taste of many dishes without greatly increasing the amount of energy. The onion contains phenols and flavonoids, these have anti-inflammatory effects, positive effects on cholesterol balance, prevent cancer and act as antioxidants. The benefits of antioxidants for the human body are numerous. Shallots are particularly rich in them. They contain up to six times more antioxidants than, for example, yellow onions. Furthermore, very positive effects on blood sugar levels have been noted. Onions can lower blood pressure and prevent heart disease. Some people have allergic reactions to contact with onions (itching, asthma). Nevertheless, consumption is usually harmless for these people, as the responsible proteins are rendered ineffective by the preparation. While consumption is safe for humans, feeding raw onions to dogs, cats, guinea pigs or other animals can be fatal. These are unable to digest the vegetable. Some Indian sects forbid the consumption of onions because they are considered an aphrodisiac. Schools of Buddhism also discourage onions because they are said to stir up desire in cooked form and anger in raw form.When cutting onions, enzymes contained in the cells are released, which develop into sulfenic acids when exposed to air. These can cause irritation in the eyes. Cooling the onion or cutting it under warm water can help. However, the more frequently a person cuts onions, the less susceptible he or she is to the reaction to the sulfenic acid.
